Php Session Redirect Page

Question

Okay, What I have here is a simple php login session. Sometimes session destroy even I don't destroy the session. In my Index.php, there's a link for editing record. My problem is, if session destroy and I click edit, the page open's in modal or fancybox and shows login.php and after I login it's goes to index.html. What I need to do is instead of going into index.html, I need to redirect to edit.php with GET value to continue the edit process. Any help?

Index.php

<a class="fancybox" href="edit.php?pn='.$row["id"].'"><img src="images/edit.png"></a>

Edit.php

<?php 
session_start();
include('connect.php');
$tbl_name="login_admin";
if(! isset($_SESSION['id'])){
header('location:login.php');
exit;
}
$id = $_SESSION['id'];
$sql = $mysqli->query("SELECT * FROM $tbl_name WHERE username='$id'");
$accounts   = $sql->fetch_assoc();

$term= $mysqli->real_escape_string($_GET["pn"]);
?>

Login.php

<?php
require_once('connect2.php');

session_start();
$username = $_POST['username'];
$password = $_POST['password'];
$submit = $_POST['submit'];

if($username && $password){
$sql = sprintf("SELECT * FROM $tbl_name WHERE username='$username' AND password='$password'");
$result = @mysql_query($sql);
$accounts = @mysql_fetch_array($result);
}
if($accounts){
$_SESSION['id'] = $accounts['username'];
header("location:index.html");
exit;
}elseif($submit){
$msg = 'Invalid Username or Password';
}
?>

Answer 1

Unfortunately you can't continue the edit process, but you can redirect user to edit page after login.

There are more ways how to to it, I will show one of them.

1. before redirecting user to login script, save his original URL to session (another way would be to pass it to login.php as GET parameter - don't forget validation in that way):

Edit.php:

<?php 
session_start();
include('connect.php');
$tbl_name="login_admin";
if(! isset($_SESSION['id'])){
    $_SESSION['original_url']=$_SERVER['REQUEST_URI']
    header('location:login.php');
    exit;
}
// rest of the code.....

1. Then redirect user to that page instead of default index.html page

Login.php:

<?php
require_once('connect2.php');

session_start();
$username = mysql_real_escape_string($_POST['username']);
$password = mysql_real_escape_string($_POST['password']);
$submit = $_POST['submit'];

// Security note: see I've sanitized $username and $password with mysql_real_escape_string() to avoid SQL injection
if($username && $password){
    $sql = sprintf("SELECT * FROM $tbl_name WHERE username='$username' AND password='$password'");
    $result = mysql_query($sql);
    $accounts = mysql_fetch_array($result);
}

// when account was found store identity to session
if($accounts){
    $_SESSION['id'] = $accounts['username'];

    if (isset($_SESSION['original_url']) {
        // if user came from internal url, redirect to it and remove it from session
        $originalUrl = $_SESSION['original_url'];
        unset($_SESSION['original_url']);
        header("location:".$originalUrl);
        exit;
    } else {
        // redirect user to default page after login
        header("location:index.html");
        exit;
    }

} elseif($submit){
    // login form was sent, but user with given password not found
    $msg = 'Invalid Username or Password';
}
?>